block: add block_job_query

Extract it out of the implementation of info block-jobs.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/blockjob.c b/blockjob.c
index 9737a43..dea63f8 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -161,3 +161,14 @@
         job->busy = true;
     }
 }
+
+BlockJobInfo *block_job_query(BlockJob *job)
+{
+    BlockJobInfo *info = g_new0(BlockJobInfo, 1);
+    info->type   = g_strdup(job->job_type->job_type);
+    info->device = g_strdup(bdrv_get_device_name(job->bs));
+    info->len    = job->len;
+    info->offset = job->offset;
+    info->speed  = job->speed;
+    return info;
+}